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Funding Acknowledgements Type of funding sources: Foundation. Main funding source(s): Velux Stiftung Background Ageing of cardiomyocytes (CM) involves structural and functional adverse remodelling that finally could result in heart failure (HF) insurgence, which incidence rise along with age (1). Current medical therapies for HF may not always be tolerated in elder patients(2). Having shown that cardiac progenitor cells (CPCs) secrete nanoparticles named exosomes (EXO) enriched of cardioprotective factors(3,4), we are exploring EXO's capacity to ameliorate senescence-derived modification into CMs. However, human models of in vitro cardiac aging are currently missing(5). Aim This study exploits CMs derived from human induced pluripotent stem cells (hiPSCs) as an in vitro model for cardiac senescence, that will be used as platform to characterize mechanisms involved in cardiac ageing and to test protective effect of CPC-derived EXO. Methods Patient-derived CPCs were reprogrammed into hiPSCs and subsequently expanded and differentiated into cardiomyocytes (hiPSC-CMs). Senescence-like phenotype was induced by short exposure (3 hours) to doxorubicin (DOX) at sub-lethal concentration (0.2 µM), followed by washing and medium change. Following DOX exposure, cells were exposed to EXO, derived from the purification of conditioned culture media of CPCs using an ultracentrifugation-based isolation method and quantified and sized using a NTA counter. Senescence induction was highlighted by protein and gene expression analysis and senescence-associated b-galactosidase (SA-β-gal) assay.Electrical activity of hiPSC-CMs was evaluated recording extracellular field potentials through multi-microelectrode arrays (MEA) and by single cell patch clamp. Metabolic features were analysed with western blot, real time RT-PCR and specific biochemical assays. Results DOX treatment in hiPSC-CMs induced senescence, as confirmed by activation of p21 and p16 pathways and increasing of SA-β-gal staining as compared to untreated cells (CTR). Biochemical and gene expression analysis revealed an increased ROS production and a reduction in mitochondrial potential, which drives a strong decrease in the ATP/AMP ratios. Real Time PCR analysis reveal an increased transcription of molecules related to the senescence associated secretory phenotype in DOX-CMs. Moreover, DOX-CMs showed impaired Ca++ handling, prolonged multicellular QTc and single cell APD, with increased APD variability and delayed afterdepolarizations (DADs) incidence in comparison to CTR. EXO treatment mitigated the senescent phenotype induced by DOX, as shown by a decreased ROS induction, higher mitochondrial potential which drives a restored ATP/AMP ratio. Furthermore, DOX-induced QTc prolongation was prevented by EXO treatment. Conclusion Our hiPSC-CMs based cellular model recapitulates the phenotype of aged CMs in terms of senescence markers, electrical and metabolic proprieties. CPC-derived EXOs limit age-related modifications, highlighting the cardioprotective role of small molecules released by EXO. Open in new tab Download slide Graphical Abstract [ABSTRACT FROM AUTHOR]

Rationale: Aging in the heart is a gradual process, involving continuous changes in cardiovascular cells, including cardiomyocytes (CMs), namely cellular senescence. These changes finally lead to adverse organ remodeling and resulting in heart failure. This study exploits CMs from human induced pluripotent stem cells (iCMs) as a tool to model and characterize mechanisms involved in aging. Methods and Results: Human somatic cells were reprogrammed into human induced pluripotent stem cells and subsequently differentiated in iCMs. A senescent-like phenotype (SenCMs) was induced by short exposure (3 hours) to doxorubicin (Dox) at the sub-lethal concentration of 0.2 µM. Dox treatment induced expression of cyclin-dependent kinase inhibitors p21 and p16, and increased positivity to senescence-associated beta-galactosidase when compared to untreated iCMs. SenCMs showed increased oxidative stress, alteration in mitochondrial morphology and depolarized mitochondrial membrane potential, which resulted in decreased ATP production. Functionally, when compared to iCMs, SenCMs showed, prolonged multicellular QTc and single cell APD, with increased APD variability and delayed afterdepolarizations (DADs) incidence, two well-known arrhythmogenic indexes. These effects were largely ascribable to augmented late sodium current (I NaL ) and reduced delayed rectifier potassium current (Ikr). Moreover sarcoplasmic reticulum (SR) Ca 2+ content was reduced because of downregulated SERCA2 and increased RyR2-mediated Ca 2+ leak. Electrical and intracellular Ca 2+ alterations were mostly justified by increased CaMKII activity in SenCMs. Finally, SenCMs phenotype was furtherly confirmed by analyzing physiological aging in CMs isolated from old mice in comparison to young ones. Conclusions: Overall, we showed that SenCMs recapitulate the phenotype of aged primary CMs in terms of senescence markers, electrical and Ca 2+ handling properties and metabolic features. Thus, Dox-induced SenCMs can be considered a novel in vitro platform to study aging mechanisms and to envision cardiac specific anti-aging approach in humans., Competing Interests: Competing Interests: The authors have declared that no competing interest exists., (© The author(s).)

Aims: Diabetic cardiomyopathy is a multifactorial disease characterized by an early onset of diastolic dysfunction (DD) that precedes the development of systolic impairment. Mechanisms that can restore cardiac relaxation improving intracellular Ca2+ dynamics represent a promising therapeutic approach for cardiovascular diseases associated to DD. Istaroxime has the dual properties to accelerate Ca2+ uptake into sarcoplasmic reticulum (SR) through the SR Ca2+ pump (SERCA2a) stimulation and to inhibit Na+/K+ ATPase (NKA). This project aims to characterize istaroxime effects at a concentration (100 nmol/L) marginally affecting NKA, in order to highlight its effects dependent on the stimulation of SERCA2a in an animal model of mild diabetes., Methods and Results: Streptozotocin (STZ) treated diabetic rats were studied at 9  weeks after STZ injection in comparison to controls (CTR). Istaroxime effects were evaluated in vivo and in left ventricular (LV) preparations. STZ animals showed (i) marked DD not associated to cardiac fibrosis, (ii) LV mass reduction associated to reduced LV cell dimension and T-tubules loss, (iii) reduced LV SERCA2 protein level and activity and (iv) slower SR Ca2+ uptake rate, (v) LV action potential (AP) prolongation and increased short-term variability (STV) of AP duration, (vi) increased diastolic Ca2+, and (vii) unaltered SR Ca2+ content and stability in intact cells. Acute istaroxime infusion (0.11 mg/kg/min for 15 min) reduced DD in STZ rats. Accordingly, in STZ myocytes istaroxime (100 nmol/L) stimulated SERCA2a activity and blunted STZ-induced abnormalities in LV Ca2+ dynamics. In CTR myocytes, istaroxime increased diastolic Ca2+ level due to NKA blockade albeit minimal, while its effects on SERCA2a were almost absent., Conclusions: SERCA2a stimulation by istaroxime improved STZ-induced DD and intracellular Ca2+ handling anomalies. Thus, SERCA2a stimulation can be considered a promising therapeutic approach for DD treatment., (© The Author(s) 2021. Published by Oxford University Press on behalf of the European Society of Cardiology.)

The present review aims toward a better understanding of the nutrition of newborn puppies and kittens. The post-natal period is very sensitive in dogs and cats, as in other animal species. During the first two weeks of life, puppies and kittens are at high risk of dehydration, hypothermia, and hypoglycemia, as well as infectious diseases as they start to acquire the physiological functions of the adult. Neonatal hepatic glycogen storage is low, and newborns depend on colostrum intake to survive. Colostrum provides immunoglobulins and other important substances such as lipids and carbohydrates. Immunoglobulins are central to the immunological link that occurs when the mother transfers passive immunity. The mechanism of transfer varies among mammalian species, but in this review, we focused our attention on dogs and cats. Furthermore, there are components of colostrum which, although their presence is not absolutely necessary, play an important role in nutrition. These components have received considerable interest because of their presumed safety and potential nutritional and therapeutic effects both in humans and animals; however, unfortunately, there are few recent studies in companion animals. Here, we have gathered the published articles that describe studies involving different species of animals, emphasizing companion animals. In particular, the purpose of this narrative of the nutritional and functional proprieties of queens' and bitches' colostrum.

The use of transgenic plants as delivery system for antigenic proteins is attractive for its simplicity and increases likelihood for local immune response at sites of infection. The aim of this study was to evaluate the protective effect of oral administration of tobacco seeds, expressing the FedA, the major protein of the F18 adhesive fimbriae, and B subunit of verocytotoxin, against verocytotoxin-producing E. coli (VTEC) strain in piglets. Forty-three early weaned piglets, were randomly divided into 4 experimental groups: 3 test groups and a control. Treatment groups orally received a bolus, with different dose of tobacco seeds on 0, 1, 2, 14 days post primary administration. After challenge, with 1*10(10) CFU of O138 Escherichia coli strain, piglets showed clinical scores significantly higher in the control group compared to orally immunized groups (P < 0.05) and the latter showed a faster recovery than in CG. In conclusion, oral administration of recombinant tobacco seeds expressing antigenic proteins against VTEC strains can induce a protective effect against challenger strain in piglets.